ITED STATES DEPARTMENT OF AGRICULTURE 

| BULLETIN No. 714 

Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 




s^&'^j-u 




Washington, D. C. 



PROFESSIONAL PAPER 



August 9, 1918 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 

By C. L. Shear and Neil E. Stevens, Pathologists ; R. B. Wilcox and B. A. 
Rudolph, Scientific Assistants, Fruit-Disease Investigations. 

(The work done in Massachusetts was in cooperation with the Massachusetts 
Agricultural Experiment Station.) 



CONTENTS. 

Page 



Introduction 1 

Causes of the cranberry spoilage 2 

Bruising 2 

Drying out 3 

Natural ripening processes 4 

Smothering 4 

Conditions which cause smothering 4 

Water storage 5 

Prevention of smothering 5 



Fungi 6 

Importance 6 

Principal cranberry fungi which cause 

fruit rots 6 

Control of fungous diseases 7 

Summary 18 

Practical suggestions 19 

Literature cited 20 



INTRODUCTION. 

IMPORTANCE OF SPOILAGE AFTER HARVEST. 

Three million dollars' worth of cranberries are, on the average, 
produced annually in the United States. Although effective control 
measures are practiced by many growers, a considerable portion of 
the crop, certainly not less than 10 per cent, is lost through fungous 
diseases before the fruit is picked. Large losses also frequently ap- 
pear after picking. In some respects this spoilage is more trouble- 
some than that which occurs earlier. Fruit which spoils after it is 
packed and shipped has cost the grower for handling and packing, 
and further expense is frequently involved in claims for allowances, 
shipments refused, inspection, and sometimes reseparating at the 
market. On the average, at least 15 per cent of the crop is estimated 
to be lost between the field and the consumer. 

A less obvious but even more serious effect upon the demand for 
and sale of cranberries is that produced by marketing spoiled fruit. 
"Time and again," says Mr. A. U. Chaney (3, p. 30) 1 , "have I no- 

1 The serial numbers in parentheses refer to "Literature cited" (p. 20). 






U. S. DEPARTMENT OF AGRICULTURE. 

ticed that a retailer who has unsound and unattractive fruit in his 
store has blocked his sale of cranberries." As the trade becomes more 
and more critical, not only of cranberries but of other fruits, the 
time is rapidly approaching when (2, p. 30) " growers must recognize 
the absolute necessity -of producing fruit that will be sound when it 
goes before the consumer." 

PLAN OF THE PRESENT WORK. 

The senior writer has carried on investigations of the diseases of 
cranberries since 1901. During the past two years (1916 and 1917), 
however, the problem has been taken up with special reference to the 
losses which occur after picking. Field work and storage experi- 
ments have been carried on in Massachusetts and New Jersey; labora- 
tory studies of material shipped from these areas and from Wiscon- 
sin, Michigan, Oregon, Maine, and West Virginia have been made at 
Washington, D. C. ; fruit has been inspected and studied in most of 
the important markets east of the Mississippi River; and experimen- 
tal shipments have been made from cranberry-growing centers to 
Washington, New York, and Chicago. So far as practicable, the 
field work in Ncav Jersey and in Massachusetts has been conducted 
along similar lines, in order to avoid errors due to peculiar local con- 
ditions. 

The investigations in Massachusetts have been carried on in co- 
operation with the Massachusetts Agricultural Experiment Station, 
the work at the State bog at East Wareham being in charge of Dr. 
H. J. Franklin (4, 5). Prof. F. W. Morse, of the experiment sta- 
tion, has also taken up certain important phases of cranberi^y respi- 
ration in relation to spoilage. While the investigations are not yet 
complete, the present paper aims to present the more important re- 
sults and the conclusions thus far obtained in order that they may 
be immediately available to cranberry growers. 

CAUSES OF CRANBERRY SPOILAGE. 

The spoilage of cranberries is due in general to one or more of the 
following causes : Freezing, insect work, bruising, drying out, natural 
ripening processes, fungous rots, and smothering. The writers pro- 
pose to employ the term smothering to designate the pathological 
conditions produced in fruits by sufficient interference with respira- 
tion, whatever the cause of this interference. 

As the cause of freezing and the means of its prevention are well 
understood and the work of insects is outside the province of this 
paper, these two causes of spoilage will not be discussed. 

BRUISING. 

Loss due to bruising is by no means confined to actual crushing of 
berries by careless handling or spilling in sorting or packing houses, 



0. of B. 



^ 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 



though this is in itself a cause of considerable loss and should be 
carefully guarded against. 

Very important and more difficult to eliminate are the numerous 
unnoticed injuries occurring in the processes of harvesting, separat- 
ing (milling), sorting (hand screening), and packing the fruit. It 
has been shown that these injuries, while too slight to affect the im- 
mediate sale of the fruit, indirectly bring about serious losses by 
starting decay. This relation of bruising to the starting of fungous 
rot will be considered later. 

Slightly injured berries also dry out and shrivel much more quickly 
than sound fruit. Shrinkage in storage will be reduced, therefore, 
by care in harvesting and handling the fruit. 

DRYING OUT. 

Cranberries held in storage will gradually shrink even though no 
decay occurs. An experienced observer (6, 1913, p. 20) estimates 
this shrinkage as high as 10 per cent in the case of Early Black cran- 
berries held in common storage at the bog for late trade. A part 
of this loss is due to the natural ripening processes mentioned below 
and part in some cases to the actual loss of water by evaporation. 
Bruising the fruit increases its rate of drying out and shriveling. 

The rate at which water is lost by evaporation depends in part di- 
rectly on the moistness of the air. In tests made by keeping weighed 
quantities of cranberries in containers with air of known humidity 
it was found that for any given temperature the loss in weight in- 
creased with the decrease in the humidity of the air. (Table I.) 

Table I. — Decrease in the weight of cranberries of the Hoioe variety held for 
36 days in air of different humidities at certain temperatures. 



Air conditions. 


Relative humidity (per cent). 


100 


80 


65 


35 


a 


Temperature 5° to 10° C (41° to 50° F.): 

Loss in weight per cent. . 

Temperature 2° to 5° C (36° to 41° F.): 

Loss in weight do 




.5 


4 
1.5 


5 
3 


6 
4.5 


9 
6 



a Over concentrated sulphuric acid. 

It is evident from these results that considerable humidity in the 
air of the storehouse is desirable to prevent the drying out of the 
fruit. Under the conditions ordinarily obtaining in cranberry store- 
houses the humidity is sufficient to prevent any serious loss from dry- 
ing. In New Jersey the higher temperatures after picking are favor- 
able for drying, and under some conditions of storage fruit kept for 
a long time may actually shrivel. 

It should be mentioned in this connection that in a series of tests 
extending through both 1916 and 1917, in which cranberries of both 



4 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 

the Early Black and the Howe varieties were kept in containers of 
known humidity, using a method already described by one of the 
writers (13), no direct relation was found between the humidity of 
the air and the amount of rot of the fruit. Berries kept as well in 
very moist air as in drier air unless they were actually wet. 

NATURAL RIPENING PROCESSES. 

Like other fruits, the cranberry when picked is a living organism, 
carrying on its vital activities, which may be referred to in general 
as ripening processes. Of these processes one of the most important 
is respiration. Under normal conditions the respiration of a fruit 
is marked by taking in oxygen and giving off carbon dioxid. In this 
process the living matter of the fruit is broken down and the berry 
gradually loses weight. If continued long enough this process would 
end in the destruction of the berry. It has been demonstrated that 
respiration goes on more rapidly at high than at low temperatures; 
consequently, the cooler the berries can be kept without freezing the 
longer they will live and the better will be their condition. 

SMOTHERING. 

CONDITIONS WHICH CAUSE SMOTHERING. 

In a paper published with the report of the Massachusetts 
Cranberry Station for 1916 (11) the writers called attention to 
the spoilage of cranberries caused by insufficient ventilation. As 
pointed out at that time, cranberries kept in tight cans or in an 
atmosphere of carbon dioxid lose their crispness and bright color, 
become dull red and flaccid, and taste bitter. Since this kind of 
spoilage is apparently caused by conditions which check normal 
respiration, the writers designate it as smothering. Experience has 
shown that whenever cranberries of good keeping quality are cov- 
ered with some inert gas, such as carbon dioxid, buried for some 
time in a big pile of berries, shut up in a tight container, kept under 
water, or subjected to other conditions which prevent normal res- 
piration, smothering occurs. The exact causes of this spoilage, as 
well as the nature of the changes brought about in the fruit, are now 
the subject of investigation by Prof. F. W. Morse, of the Massa- 
chusetts Agricultural Experiment Station. 

AVhen berries are under water or under carbon dioxid, death due 
to smothering occurs in a short time, often in one to two weeks, 
whereas in tight containers or in large piles it results so slowly that 
if the berries are of inferior keeping quality fungous rot may de- 
stroy them before the effect of smothering appears. In case rot- 
producing fungi are present, they develop rapidly on the weakened 
berries, and a mass of rotten fruit results. 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 5 

WATER STORAGE. 

Storing cranberries under water is frequently recommended as a 
means of keeping them for long periods. Berries stored in this way 
soon die as a result of smothering. They can not, however, wither, 
nor do they decay, since the growth of rot-producing fungi is pre- 
vented. Water-stored berries do not have the bitter taste character- 
istic of most smothered fruit and are therefore suitable for cook- 
ing if used as soon as removed from the water. Such berries are, 
of course, unsalable. 

The eifect of storing cranberries in tight packages and under 
water as compared with storage in ventilated packages was shown 
by a series of tests made at the State experimental cranberry bog, 
East Wareham, Mass. In one experiment, uniform lots of appar- 
ently sound berries, of both the Early Black and the Howe varie- 
ties, were stored dry in closed bottles, under water in bottles, and in 
ventilated boxes. The results of this test are given in Table II. 

Table II. — Results of storing cranberries under different conditions for 36 

days. 



Conditions of storage. 


Number of berries. 


Total 
spoiled 


Total. 


Rotten. 


Smothered. 


(per 
cent). 


Temperature 3° to 8° C (37° to 46° F.): 

Under water, in bottle 






777 
382 


All. 

None apparent. 




a ioo 




1,054 
1,364 


74 

28 







a As explained in the text, these berries were still fit for cooking. 

The results shown in Table II are typical of those obtained in other 
tests, some of which were carried out at much higher temperatures 
and with other varieties of cranberries, and have been further sub- 
stantiated on a commercial scale by shipments in various types of 
packages and by storage tests. These will be considered later. 



PREVENTION OF SMOTHERING. 

Smothering may be prevented by ventilation. Berries should be 
stored in ventilated boxes, never in barrels, and the boxes should be 
so piled as to allow circulation of air through the berries. Cran- 
berry storehouses should be provided with ventilators, which should 
be opened whenever cold air can be admitted without danger of 
freezing. Ventilated packages should be used where practicable. 
These points are also of importance in the control of fungous dis- 
eases and are discussed further in that connection. 



6 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 

FUNGI. 

IMPORTANCE. 

The writers' observations (10) indicate that rot-producing fungi 
cause at least one-half of all the loss in cranberries after picking. 
These fungi are, however, by no means of uniform importance in 
different regions or in different seasons. A study of a number of 
neighboring bogs during a single year or of a single bog through a 
series of years can not fail to impress the investigator with the ex- 
treme variation in the loss due to decay. 

An illustration of the variation in the amount of rot over a con- 
siderable area in different seasons is found in the annual reports of 
the board of inspectors of the New England Cranberry Sales Co. for 
the last five years, as given by the chairman, Mr. H. S. Griffith (6). 
The crop of 1913 was described as "remarkably free from fungous 
disease"; in 1914 and in 1915 there was a large percentage of un- 
sound fruit; the crop for 1916 was unusually sound up to November 
1, after which a noticeable, though not very serious, amount of end- 
rot developed; the crop for 1917 was in general of good keeping 
quality, with a small amount of fungous disease. As these inspectors 
determine the brand of the crops from representative bogs over much 
of the Massachusetts cranberry area, their reports, no doubt, repre- 
sent fairly well the condition for the entire region. 

The prevalence of rot in some seasons seems to be associated with 
weather conditions which would favor the growth and spread of 
fungi. Our knowledge of these relations is too slight, however, to 
permit of very definite conclusions. Differences in the amount of 
rot on different bogs or on various portions of one bog are often 
related either to lack of vigor or to excessive growth of the vines, 
due to various causes. These relations will be considered later. 

PRINCIPAL CRANBERRY FUNGI WHICH CAUSE FRUIT ROTS. 

The fungi which cause the decay of cranberries after they are 
picked are in a large part those which attack the fruit on the vines. 
The molds which cause decay of such perishable fruits as strawberries 
and raspberries are rarely found on cranberries and are, therefore, 
of slight importance. 

Among the diseases which are the principal causes of losses of 
cranberries in storage are early-rot (8), caused by Guignardia vac- 
cina Shear, which is also the cause of scald and blast, and which is 
especially destructive to fruit on the vines and early in the season 
in New Jersey; end-rot (9), caused by Fusicoccum putrefaciens Shear, 
common on fruit in storage, especially late in the season and in the 
northern cranberry regions; bitter-rot, caused by Glomerella cingu- 
lata vaccinii Shear; ripe-rot, caused by Sporonema oxy cocci Shear; 
and blotch-rot, caused by Acanthorhynchus vaccinii Shear. Soft-rot, 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 7 

caused by Penicillium spp., is rather common on fruit held late in 
storage, but is usually associated with other rots, and is not of great 
importance. Ripe-rot develops at a lower temperature than any 
of the other rots, except end-rot, and is most frequent in Massa- 
chusetts. 

CONTROL OF FUNGOUS DISEASES. 
Bog Management. 

Since all the fungi which cause important storage rots of cran- 
berries are found on the bogs and in large part gain entrance to the 
berries before they are picked, control measures should begin with 
the bog. Not all of the factors which determine the abundance of 
fungi are understood at present; in fact, it sometimes seems as if 
a bog is free from rot-producing fungi in spite of the treatment it 
receives rather than because of its management. Certain phases of 
bog management seem, however, to have a direct relation to the 
keeping quality of the fruit produced. An excessive growth of vines, 
whether produced by too much nitrogenous plant food or some other 
cause, generally results in diseased fruit. 

Many cranberry growers believe that frequent flooding to prevent 
injury from early frosts in the fall seriously affects the keeping qual- 
ity of the fruit, although this is not uniformly the case. The writers 
had under observation one bog which during the fall of 1917 was 
completely submerged on 12 nights, and the fruit still showed excep- 
tional keeping quality. 

If the water is held for a considerable period continuously, how- 
ever, the result is very likely to be disastrous. Cranberries of the 
Early Black variety on the Massachusetts State bog, which had been 
submerged for two weeks after the bulk of the crop was harvested, 
showed a great increase in the rot of the flooded fruit as compared 
with the fruit harvested before the flooding. In this case, indeed, 
a serious infection of Sporonema oxy cocci (ripe-rot) occurred on the 
berries which had been submerged. Only a few of the berries picked 
before this flooding were found to be infected with this fungus. In 
northern cranberry regions during cold periods bogs are sometimes 
flooded and the water held so long that the fruit may be actually 
smothered. This practice is certain to injure the fruit. 

The holding of winter flowage until mid-July, thus sacrificing one 
season's crop, is occasionally practiced in both Massachusetts and 
New Jersey as a means of reducing pests; this is one of the treat- 
ments recommended by Franklin (4) and by Scammell (7) for the 
reduction of several destructive insects. During the year following 
this treatment a large crop of berries of excellent keeping quality is 
said to be obtained, and the benefits, both in the reduction of field 
rot and in the improvement of keeping quality, are frequently said 
to persist for several years. 



8 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 

Spraying. 

Thorough spraying has been found in all localities to reduce rot 
and improve the keeping quality of the fruit. In New Jersey and 
on Long Island, where there is always considerable loss from fun- 
gous disease before picking and where spraying has been practiced 
in some cases for 10 years, thorough spraying has been found 
profitable and no injury to the vines has been observed. 

Experiments were conducted with the Early Black variety at 
Whitesbog, N. J., during 1917 to determine the times at which 
Bordeaux mixture should be applied in order to control fungous dis- 
eases most effectively and economically. Blast, early-rot, and a 
storage rot, all due to Guignardia vaccinii Shear, were the principal 
causes of loss on this bog during the year. Bordeaux mixture of 
the formula 4—4-50, with about 1 pound of resin-fishoil soap, was 
used throughout the experiments. 

A single thorough application of Bordeaux mixture after the blos- 
som buds had begun to open increased the total yield by more than 
10 per cent (from 173 to 192 bushels per acre) by controlling blossom 
blast. Two applications before blossoming were no more effective 
than one. An application immediately before the spring refiow 
showed no effect in the control of fungi. No trace of the spray was 
observed on the vines when the water was removed. The applica- 
tions before blossoming had no effect in reducing the rotting of the 
fruit after picking. 

Protection of the berries from infection during the first month 
of their growth resulted in very satisfactory control of both field 
and storage rots. This was accomplished b}^ two thorough applica- 
tions, one near the close of the blossoming period (before all the 
petals had fallen) and another two weeks later. By these applica- 
tions alone the total yield was increased, the rot at picking time was 
reduced from more than 20 per cent to less than 2 per cent, and stor- 
age rot from 6.7 per cent to 1.9 per cent. These two sprays applied 
at the proper time effected a saving of 44 bushels of marketable 
cranberries per acre, or one-fourth of the crop. Any delay in mak- 
ing the first application after blossoming resulted in a marked in- 
crease in both field rot and storage rot. 

A third application after blossoming was of no increased benefit 
in these experiments. It must be repeated, however, that early-rot 
was the only fungous trouble of importance on this bog; furthermore, 
the berries were picked before the middle of September. It is doubt- 
ful whether two applications after blossoming will give satisfactory 
control with all varieties or where other diseases, such as bitter-rot, 
are concerned. A similar series of experiments with cranberries of 
the Centennial variety in New Jersey during 1917 gave unsatisfactory 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 



9 



and unreliable results because of severe frost injury. Further ex- 
periments along this line are necessary and are in prospect. 

The use of Bordeaux mixture with resin-fishoil soap, which has 
been found to be the most effective fungicide for cranberries, is 
recommended. One application should be made just after the blos^ 
soms begin to open and should be repeated every two weeks until 
August 15. 

In Massachusetts small plats of berries on the State bog which 
were sprayed with Bordeaux mixture for several years in succession 
have shown some injury to the vines. More experiments are neces- 
sary in order to determine the cause of this injury. As no injury 
of this kind has been observed in New Jersey or on Long Island, 
the writers feel that where losses from rot either before or after pick- 
ing are heavy the benefit from spraying will more than offset any 
probable injury. 

Dry Picking. 

Experiments conducted on a number of bogs in New England 
have indicated that cranberries should be picked dry. The results 
shown in Table III are summarized from tests made in 1917. In 
each case from 4 to 10 bushels of berries were picked early in the 
morning while still wet with dew and an equal quantity taken from 
an adjacent portion of the bog as soon as the berries were thor- 
oughly dry. 

Table III. — Comparative results of storing cranberries that were picked wet 

and dry in 1917. 



Variety. 



Locality. 



Davs in 
storage. 



Percentage ol rotten 
cranberries. 



Picked dry. Picked wet 



Early Black. 

Howe 

Early Black. 
Cherry 



East Wareham, Mass.. 

do 

South Wareham, Mass. 
Madrid, Me 



32 
13 
a 17 
2.4 



51 
40 
a 20 
6.0 



a Contained about 10 per cent of rotten berries when picked. 

That the inferior keeping quality is due to the fact that the berries 
were wet and not to any injury received in picking is indicated by 
the fact that similar deterioration in keeping quality followed where 
boxes of berries which had been picked dry were wet with clean 
water. 

During the latter part of the shipping season cranberries are some- 
times removed from a cool storage house to a warm room for sort- 
ing and packing. If the humidity of the air is high, moisture fre- 
quently condenses on the berries to such an extent that they become 
wet and sticky. This is injurious to their keeping quality and should 
be carefully avoided. Cranberries should never be barreled or 
shipped in this condition. The desirability of packing and, if pos- 
61728°— 18— Bull. 714 2 



10 



BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 



sible, sorting in cool rooms, which will prevent wetting the fruit by 
condensation from the air, is further considered under the next 
topic. 

Low Temperature. 

5 A study of the temperature relations of many of the fungi which 
cause fruit rots of cranberries (14, pp. 524 and 525) has shown that 
most of them grow very slowly, if at all, below 10° C. (50° F.). 
The only conspicuous exception is the end-rot fungus, which grows 
somewhat even at 0° C. (32° F.). The rate of growth of all these 
fungi, and consequently of the rot which they cause, increases rapidly 
with rise of temperature above 10° C. (50° F.). As already men- 
tioned, the ripening processes which result in the death of the cran- 
berry itself also go on more rapidly as temperature rises. 

As an illustration of the effect of temperature on the keeping 
quality of cranberries, the results of temperature tests conducted at 
Washington, D. C, during 1916 and 1917 may be cited (Table IV). 
Equal quantities of apparently sound cranberries from uniform lots 
were kept at different temperatures in the refrigeration apparatus 
described by Brooks and Cooley (1). 

Table IV. — Effect of temperature on the keeping quality of cranberries as shown 
by tests made at Washington, D. C, in 1916 and 1917. 





Days in 
storage. 


Percentage of cranberries spoiled in storage at temperatures — l 


Variety. 


0°0, 
(32° F.). 


5°r. 

(41° P.). 


10° C 
(50° F.). 


15° C. 
(59° F.). 


20° C. 

(68° F.). 


Early Black 


28 
2* 
25 
60 
60 
56 
67 


2 

1 

2.5 
16 
20 
39 

8 


4 
1.5 

5 
27 
27 
43 
27 


5 
3.5 

8 


12 
9 
15 5 

48 
51 
92 

4S 


19 


Do 


13 




19 


Earlv Black 


72 


Do 




66 


Do 




99 


Howe 




76 









i This includes smothering and all forms of fungous rot. 

In the course of the first three tests, the results of which are civen in Tabie IV, it was observed that cran- 
berries color more rapidly at relatively low temperatures (5° O., 41 u F.). It is, then, desirable from every 
point of view for cranberries to be kept as cool as practicable. 

When cranberries are picked they are usually at a temperature 
considerably warmer than that of the air, and the sooner they are 
cooled the better. To this end it is desirable that cranberries should 
be removed from the bog as soon as practicable and placed in the 
shade. They should be stored in ventilated boxes, never in barrels, 
and the boxes should be so piled as to permit free circulation of air 
among the boxes. 

The storehouse in which cranberries are held should be kept as 
cool as is possible without danger of freezing the fruit. This can 
be done most economically by having the house provided with ade- 
quate ventilators to admit air at the bottom of the building. These 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 



11 



ventilators should be open during cool weather and closed when the 
temperature of the outside air rises above that of the storehouse. 

As already stated, cranberries which are held in the chaff and 
shipped during cold weather are frequently brought from a cold to 
a warm room for sorting. In order that sorters may work com- 
fortably and efficiently the room in which the work is done must 
be at a temperature of at least 15° C. (60° F.), while the fruit in 
storage is often at a much lower temperature. If cool cranberries 
are held in a warmer room long enough for proper screening, their 
temperature is considerably raised, and if they are barreled in this 
room the higher temperature may be maintained long enough to 
affect their keeping quality seriously. As an instance of the injury 
to keeping quality which may result from such treatment, a test 
made in the fall of 1916 may be cited. Equal quantities of Early 
Black cranberries were taken from a barrel which had been kept 
for some time at a temperature of 7° to 10° C. (45° to 50° F.). One 
portion was taken to a warm room, about 24° C. (75° F.), and care- 
fully hand sorted, the process taking in all about 40 minutes, after 
which the sound berries were returned to the original temperature. 
An equal portion was sorted in the cool room. At the end of 10 
days the two lots were again sorted, with the results shown in 
Table V. 



Table 



V. — Comparative results of sorting cranberries in warm and in cool 
rooms, in the autumn of 1916. 



Treatment. 


Number of 
berries. 


Berries rotten 10 days 
after sorting. 




Number. 


Per cent. 


Sorted in a warm room „ 


973 
968 


153 

88 


17 


Sorted in a cool room 









To avoid loss from this source and from wetting the fruit by con- 
densation from the air, berries should not be sorted in a heated room 
unless necessary. When weather conditions make this imperative 
they should be removed from the warm room as soon as possible 
and should not be packed in the sorting room. Packing in a warm 
room means including in the barrel a quantity of warm air, which 
in a tight package retains its heat for a considerable time. 

Perhaps the most efficient means of overcoming this difficulty is 
one that can be readily arranged where sorting belts are used. This 
method is used by at least two growers, one in Massachusetts and the 
other in New Jersey. The separators and packers are in a large room 
which is kept at the temperature of the fruit, while the belts carry- 
ing the fruit to be sorted pass through a smaller inside room which 



12 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 

is kept at a higher temperature and in which the sorters work. 
With such a system, using belts 30 feet long, no berry is exposed to 
warm air for more than 1 minute and the air in which the berries 
are packed is as cool as that in which they were stored. Careful 
temperature tests made in such a sorting house in Massachusetts 
showed that with the temperature of the berries at 7° C. (45° F.) and 
that of the sorting room at 18° C. (65° F.), the temperature of the 
berries was raised not more than 1 degree centigrade in sorting. 

Ventilation- 
Adequate ventilation of the cranberry storehouse is necessary first 
of all as a means of lowering the temperature of the fruit as soon 
as possible after it is picked. Its importance is not by any means 
confined to the effect on temperature, however, for, as pointed out 
earlier, improper ventilation results in smothering and sometimes in 
increased decay. In order to obtain the best results, cranberries 
should be stored in ventilated boxes which are so piled as to permit 
a free circulation of air among the berries. 

The same principle may well be extended to the packages in which 
cranberries are shipped, particularly for the early shipments, which 
are frequently made during very warm weather. In this connection, 
the writers carried on experiments during both 1916 and 1917, in 
which berries were shipped in containers of different types. The 
results of these experiments are summarized in Table VI. In general 
it may be stated that the fruit in the smaller, well- ventilated con- 
tainers kept better than that in the barrels. Of these containers the 
ventilated half-barrel box is perhaps the most satisfactory. 

Ventilated barrels in which there are from 28 to 32 small openings 
(every other stave having two notches in each side) offer a convenient 
substitute for the tight barrel and one which may be introduced at 
slight expense and without the delay and effort incident to intro- 
ducing a new package to the trade. Such barrels are now in use for 
early shipments by at least one large grower. While the writers 
have as yet been unable to carry out satisfactory comparative tests 
of ventilated and tight barrels, in a simple shipment of Early Black 
cranberries from Massachusetts the berries in the ventilated barrels 
appeared drier than those in the tight barrels. It is hoped that next 
season it will be possible to make shipping tests of a size sufficient 
to settle the question as to the amount of advantage derived from 
using ventilated barrels. 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 



13 



Table VI. — Shipping tests of cranberries in different types of containers during 

1916 and 1917. 





Year. 


Point of shipment. 


Point of receipt and 
examination. 


Percentage of spoilage. 


Variety. 


In tight 
barrel. 


In venti- 
lated crate. 


Earlv Black 


1916 

1916 

1916 

1*917 

917 


East Wareham, Mass. . 
South Wareham, Mass. 
East Wareham, Mass. . 
do 


Washington, D. C 

Livermore Falls, Me.. 
Washington, D. C 


38 
23 
21 
22 
13 


29 


Do 


16 


Howe 


11 


Do 


a 18 


Do 


Wareham, Mass 




9 









a Ventilated half-barrel box. 

In this connection it may be noted that cranberries color better in 
well-ventilated containers. 

Careful Handling:. 
DECAY INCREASED BY BRUISING. 



Bruises caused in harvesting, separating, or sorting cranberries 
form, as already stated, an important cause of increased decay. This 
was strikingly shown by a test made at Whitesbog, N. J., in 1916. 
using Centennial cranberries immediately after harvesting, before 
they had been separated or sorted. Each berry in a 10-pound sample 
was examined critically for the presence of scratches, bruises, or 
other blemishes which w T ere so slight as not to be noticed in a casual 
inspection or picked out by the most careful sorter. Nearly one- 
fourth of the berries were found to be so injured; all of them were 
marketable and, to the inspector, apparently sound; they showed no 
signs of fungous decay. The injured and uninjured berries were 
placed in separate ventilated corrugated paper boxes and left in the 
storage house for two months. At the end of that time they were 
reexamined and the results noted, as shown in Table VII. 

Table VII. — Relation of slight injuries to the keeping quality of cranberries, 
as shoicn by a test made at Whitesbog, N. J., in 1916. 



Condition before storage. 


Number of 
berries. 


Rotten after being 
stored two months. 




Number. 


Per cent. 




2,171 
697 


97 
316 


4.5 




45.3 







Table VII shows that after two months in storage there was ten 
times as much rot among the previously bruised berries as in the 
sound ones. Many of these unnoticed injuries occur in each process 
of handling the fruit. This emphasizes the need of care and of 



14 



BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 



improvement when possible in methods of harvesting, separating, 
sorting, and packing cranberries. 

HARVESTING. 

Careful experiments in which the keeping quality of hand-picked 
cranberries was compared with that of scooped berries have not 
shown airv very decided advantage in favor of either method, pro- 
vided the scoopers were not allowed to pick up dropped berries from 
the ground. 

A series of tests in New Jersey in the fall of 1916 showed that the 
keeping quality of these dropped berries was much inferior to that 
of berries picked or scooped from the vines. The results of these 
tests are summarized in Table VIII. The experiment with Early 
Black cranberries was conducted by Mr. Franklin S. Chambers. 
Adjacent similar plats of each variety were marked on the bog; then 
the berries from half the plats were picked by hand by experienced 
pickers and the remainder harvested by experienced scoopers. All 
berries were stored for two months in ventilated 1 -bushel boxes in 
adjacent piles in a ventilated storage house. 

Table VIII.— Effect of different methods of harvesting upon the keeping quality 
of cranberries, as shown by tests made in New Jersey in 1916. 





Method of harvesting. 


Total 

weight 

(pounds). 


Condition noted (per cent). 


Variety. 


Immediately after 
harvesting. 


Rotten 
after 

being 
stored 2 
months. 


Rot 
developed 
in storage. 




Slightly 
bruised. 


Rotten. 


Earlv Black 


Picked 


1,168 
1,054 

171 
164 

38 
425 
384 

41 


( J ) 
0) 

12 
IS 
34 


0) 
0) 

6 

5 

6 

—1 

-1 
-1 


12 

14 

17 

12 

25 
4.5 
4.2 

18.1 




Do. 








Picked 


11 


Do. 






1)0 


Picked up after scoopers . . 
Picked 


19 




3.5 


Do. 






3.2 


Do. . 


Picked up after scoopers . . 




17.1 









Not determined. 



Berries picked up from the ground after scooping, as Table VIII 
shows, bore a much higher percentage of the slight injuries men- 
tioned above than did any of the other fruit, and, as was to be 
expected, this was the cause of their poor keeping quality. It seems 
from this evidence that if dropped fruit is picked up from the 
ground it should be kept separate, in order not to lower the grade or 
keeping quality of all the berries. 

It is probable that neither method of harvesting can be said to be 
best under all conditions, but that factors other than keeping quality, 
such as length and uniformity of pine growth, will influence or de- 
termine the method to be preferred in any particular locality. 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 15 



SEPARATING AND SORTING. 



Very important and difficult to eliminate are the numerous un- 
noticed injuries caused in the processes of separating, sorting, and 
packing the fruit. Franklin (4, p. 21) has published data which 
show that the bruising caused by running berries through the sepa- 
rator and by dropping them into a barrel markedly increases the 
amount of rot. The results of the investigation of the writers fully 
substantiate these conclusions. Great injury is also caused by squeez- 
ing the berries in sorting. In this process the decayed berries are 
often detected by touch even more than by sight, and much sound 
fruit is thus squeezed or pressed unnecessarily. The resulting bruises, 
while imperceptible, frequently serve to start decay. 

An illustration of the relation of bruises received in separating 
and sorting to the development of decay in storage is found in the 
results of a test made at Whitesbog, N. J., in the fall of 1917, in 
which 75 bushels of Early Black cranberries were picked on Septem- 
ber 11 from plats which had been thoroughly sprayed during the sum- 
mer. On September 21 the berries from each plat were divided into 
three representative parts. One part was then set aside in the storage 
house without further handling. The second part was sorted by 
hand on stationary sorting tables by commercial sorters, the percent- 
age of unsound fruit noted, and the sound berries placed in the storage 
house. The berries remaining were then separated by machine and 
finally by hand in the usual commercial manner, the percentage 
of unsound fruit noted, and the apparently sound berries placed in 
storage. In this last method practically all unsound berries were re- 
moved by the machines, and the berries therefore suffered very little 
by handling during the final process of hand sorting. 

All the berries were stored for nearly six weeks in ventilated stor- 
age boxes of 1-bushel capacity in a house in which the temperature 
varied from 15° C. to 7° C. during the season. For purposes of 
further comparison, 32 bushels of the Early Black variety that were 
picked on the same day (Sept, 14) from unsprayed plats on the 
same bog were divided, handled, and stored at the same time and in 
the same manner as those from the sprayed plats. Berries of good 
keeping quality (sprayed) were thus compared with those of poor 
keeping quality (unsprayed) as to the effect upon them of separating 
or sorting before storage. 

On October 31 all the berries were removed from storage, sorted 
by commercial sorters, and the percentage of unsound fruit noted. 
The results are summarized in Table IX. 



16 



BULLETIN" 714, U. S. DEPARTMENT OF AGRICULTURE. 



Table IX. — Increase in amount of rot due to separating or sorting cranberries, 
as shoivn by tests made at Whitesbog, N. J., in 1917. 



Conditions of test. 



Results noted (per cent). 



Rotten 
Sept. 21 
(1 week 

after 
picking). 



Total 

rotten on 

Oct. 31 

(after 6 

weeks in 

storage). 



Rot 
developed 
in storage. 



Increase 
of storage 
rot due to 

previous 
handling. 



Berries of good keeping quality (sprayed): 

Hand sorted before storage 

Separated and sorted before storage 

Not handled before storage 

Berries of poor keeping quality (unsprayed): 

Hand sorted before storage 

Separated and sorted before storage 

Not handled before storage 



1.6 



21.6 



5.9 

5.7 
3.9 

30.4 

28.3 
22.6 



4.2 
4.1 

2. 3 



6.7 
1.0 



7.8 
5.7 



Table IX shows that even with berries of excellent keeping quality 
the amount of decay developed in storage was nearly doubled by a 
previous sorting either by hand or by machine and that the effect of 
hand sorting was at least as severe as that of machine separating. 
On berries of potentially poor keeping quality the effect was similar 
but very much more marked. It appears that these berries did not 
decay in storage any faster than the sprayed berries unless they had 
been bruised previously by sorting, but that when so* bruised the rot 
developed rapidly and in large amount. Here, again, hand sorting 
alone proved slightly more injurious than separating by machine. 

This experiment indicates that the berries should be handled as 
little as possible and as late as possible before disposal, especially in 
the case of fruit of bad or doubtful keeping quality. 

As another example of the increase in the amount of decay which 
is caused by hand sorting, the results of a test made at Wareham, 
Mass., in the fall of 1917 may be cited. Ten bushel boxes of Early 
Black cranberries were scooped on September V2 in such a way that 
two boxes came from each of five different regions of the bog, the 
two boxes from each region being as nearly alike as possible. All 
the berries were stored with abundant ventilation at a temperature 
which varied from 15° to 5° C. (59° to 41° F.) as the season ad- 
vanced. Five boxes, one of each pair, were carefully hand sorted on 
October 3 and the good berries replaced in the boxes and held until 
November 6, when all the berries were sorted. The results, sum- 
marized in Table X, indicate that the sorting on October 3 more than 
doubled the amount of rot during the following month. 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 17 

Table X. — Increase in rot due to the sorting of cranberries, as shown by a 
test made at Wareham, Mass., in 1917. 





Condition noted (per cent). 


Treatment. 


Rotten on 
Oct. 3. 


Rotten on 
Nov. 6. 


Total rot. 


Sorted once dining storage 


4.3 


15.8 
11.0 


20.1 


Not sorted during storage 


11.0 









To avoid such losses as have been cited, all berries, especially those 
of doubtful keeping quality, should be handled as little as possible, 
they should be cleaned as near the time of shipping as possible, and 
in sorting care should be exercised not to touch or bruise the berries 
unnecessarily. It is possible that separating machines may be de- 
vised which will injure the fruit less than those at present in use. 
Improvement can certainly be made in the methods of hand sorting. 
The most thorough sorting is not necessarily the best if it is accom- 
panied by too much handling of the berries. Sorting belts in which 
the berries pass from the separator over a slowly moving belt which 
carries them in front of the sorters and deposits those not removed 
in a box or barrel at the end have the advantage of making it un- 
necessary for sorters to handle the fruit roughly, provided there is 
some device for turning the berries on the belt. An easer 1 of some 
kind should be used to prevent bruising when berries drop into a 
barrel or other container. 

SHIPPING IN THE CHAFF. 

When berries come from the bog they have more or less leaves, 
broken vines, or other foreign matter mixed with them. Fruit in 
this condition is said to be " in the chaff." 

As a result of the knowledge of the fact that the processes of 
cleaning cranberries increase their tendency to decay and that it is 
advantageous to place them before the consumer as soon as possible 
after cleaning, some growers have attempted shipping berries in the 
chaff and having them cleaned at destination. For berries particu- 
larly subject to decay after sorting this plan is apparently to be 
recommended. 

The writers have had the opportunity to test this method in only 
one instance, a shipment of berries from a bog in Wareham, Mass., 
to Chicago, 111. Two varieties were used in the experiment, and 
equal quantities of berries as uniform as could be secured were 
chosen. Half of each lot was carefully separated and sorted before 
shipment and the shrinkage noted; the other half was shipped in 
the chaff. At destination all lots were run through a separator and 
the shrinkage again noted. The berries were packed in Wareham on 

1 Easer is a term the writers apply to any device for breaking the fall to prevent 
bruising. 



18 



BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 



October 26 and examined in Chicago on November 15, 1917. The 
results are given in Table XI. 

Table XI. — Comparative results of shipping cranberries before and after clean- 
ing, as shoion by tests made in 1917. 





Condition when shipped. 


Shrinkage noted (per cent). 


Variety. 


In first 
cleaning. 


In sepa- 
rating at 
Chicago. 


Total. 








28.7 
10.2 
27.0 
15.5 


28.7 


Do 


Separated and sorted 


20 


30.2 




In chaff 


27.0 


Do. 


Separated and sorted 


20 


35.5 









i Contained more than 10 per cent of frozen berries. 

It will be noted that with both varieties the total loss of berries 
was greater with those cleaned before than with those cleaned after 
shipment. This is particularly marked in the case of the Middleboro 
variety, which contained no frosted berries and therefore gave a 
more accurate test. 

Shipping in the chaff naturally involves the extra expense of 
freight charges and containers for the chaff and decayed berries 
which would be taken out in cleaning. On the other hand, if fruit 
is shipped in the chaff it may be held in storage and run through a 
separator as sold. Under these conditions hand sorting will not 
be necessary and the cost of preparing for sale is materially reduced. 
In deciding whether to attempt shipping in the chaff each grower 
will have to take into consideration his own expense of separating 
and sorting, the probable keeping quality of his berries, and whether 
the consignee has adequate facilities for separating the fruit. Ship- 
ping in the chaff will then be confined to consignments to large 
dealers and will be most profitable in the case of fancy fruit of rela- 
tively poor keeping quality. 

SUMMARY. 

Recent observations and investigations have shown that about 15 
per cent of the cranberry crop is lost between the field and the con- 
sumer. The losses are due in part to fungous rots and in part to 
smothering. 

Bruising of the fruit occurs in the operations of picking, separat- 
ing, sorting, and packing. Such injury is not only a direct cause of 
spoilage, but renders the fruit much more liable to decay. Much 
more rot has been found in roughly handled or bruised fruit than 
in carefully handled fruit. 

No direct relation has been found between the humidity of the air 
in which the fruit is kept and the amount of rot which develops. 
Death and spoilage of cranberries will finally result from natural 
ripening of the fruit. This process is hastened by high temperatures 
and reduced by low temperatures. 



SPOILAGE OF CRANBERRIES AFTER HARVEST. 19 

Cranberries kept in tight packages which do not permit ventila- 
tion soon die from smothering and are of little value for food. Such 
fruit is soft and the tissues are discolored. Spoilage by smothering 
may be caused by keeping the berries in large piles, by having them 
too closely crowded in un ventilated storerooms, or by flooding for 
too long a period, especially in warm weather. 

Extended investigations indicate that at least one-half of the spoil- 
age of cranberries after picking is due to fungous rots. These vary 
much in prevalence and destructiveness in different seasons and lo- 
calities, depending upon a variety of factors. 

The chief rots which develop after picking are early-rot, caused by 
Guignardia vaccinii; encl-rot, caused by Fusicoccum putrefaciens; 
bitter-rot, caused by Glomerella cingulata vaccinii;. ripe-rot, caused 
by Sporonema oxycocci; blotch-rot, caused by Acanthorhynchus vac- 
cinii; and soft-rot caused by species of Penicillium. The fungous 
rots which develop after picking, as well as before, may be largely 
prevented by spraying with Bordeaux mixture to reduce infection. 
Improved bog management also increases the vigor of the vines and 
tends to reduce rot. 

Cranberries picked and stored or packed wet show more rot than 
those picked and packed dry; when cooled as soon as practicable 
after picking and kept at low temperatures they show a great reduc- 
tion in the amount of rot. The most favorable temperature for keep- 
ing berries is 32° F. Temperatures above 50° F. produced rapid 
increase in the development of rots. Berries warmed by being kept 
in a heated room while being sorted showed an increase in the amount 
of rot. 

Ventilated barrels or other ventilated packages used in distribu- 
tion gave less rot and other spoilage than tight packages. 

A comparison of different methods of harvesting the fruit showed 
but slight differences in its keeping quality. 

A study of the effect of separating fruit by machines and by hand 
sorting showed but little difference in the result. All lots developed 
much more rot than the check. The results indicate that separating 
and sorting should be delayed until the fruit is to be shipped. 

Cranberries shipped in the chaff, that is, without cleaning or sort- 
ing, and separated and sorted at destination, showed less loss from 
rot than those separated and sorted before shipment. 
PRACTICAL SUGGESTIONS. 

Spray thoroughly to prevent fungous infection. 

Pick and handle the fruit with great care to avoid bruising. 

Cool the berries as quickly as possible after picking and keep them 
cool until they are shipped. 

Store and handle the fruit in a cool, well-ventilated building, and 
use ventilated packages, especially for early shipments. 



LITERATURE CITED. 

(1) Brooks, Charles, and Cooley, J. S. 

1917. Temperature relations of apple-rot fungi. In Jour. Agr. Research, 
v. 8, no. 4, p. 139-164, 25 fig., 3 pi. 

(2) Chaney, A. U. 

1915. Address to the members of the New England Cranberry Sales 

Company. In Ann. Rpt. New Eng. Cranberry Sales Co., 1915, 
p. 26-37. 

(3) 1916. Address to the members of the New England Cranberry Sales 

Company. In Ann. Rpt. New Eng. Cranberry Sales Co., 1916, 
p. 23-33. 

(4) Franklin, H. J. 

1916. Report of cranberry substation for 1915. In Mass. Agr. Expt. 

Sta. Bui. 168, 48 p. 

(5) 1917. Report of cranberry substation for 1916. In Mass. Agr. Expt. 

Sta. Bui. 180, p. 183-234. 1917. 

(6) Griffith, H. S. 

1913-1917. Report [as] chairman of inspectors. In Ann. Rept. New 
Eng. Cranberry Sales Co., 1913, p. 17-24; 1914, p. 19-28; 
1915, p. 43-52 ; 1916, p. 19-22 ; 1917, p. 17-24. 

(7) Scammell, H. B. 

1917. Cranberry insect problems and suggestions for solving them. 

U. S. Dept. Agr., Farmers' Bui. 860, 42 p., 38 fig. 

(8) Shear, C. L. 

1907. Cranberry diseases. U. S. Dept. Agr., Bur. Plant Indus. Bui. 110, 
64 p., 7 pi. (2 colored). Bibliography, p. 55-57. 

(9) 1917. End rot of cranberries. In Jour. Agr. Research, v. 11, no. 2, 

p. 35-42, 3 fig., pi. A. Literature cited, p. 41. 

(10) 1917. Spoilage of cranberries after picking. In Proc. 48th Ann. Conv. 

Amer. Cranberry Grow. Assoc, 1917, p. 6-9. 

(11) Stevens, Neil E., and Rudolph, B. A. 

1917. Observations on the spoilage of cranberries due to lack of proper 
ventilation. In Mass. Agr. Expt. Sta. Bui. 180. p. 235-239. 

(12) and Wilcox, R. B. 

1918. The reduction of cranberry losses between field and consumer. In 
Proc. Amer. Cranberry Grow. Assoc, v. 48, p. 7-10. 

(13) Stevens. Neil E. 

1916. A method for studying the humidity relations of fungi in culture. 
In Phytopathology, v. 6, no. 6, p. 428-432. Literature cited, 
p. 432. 

(14) 1917. Temperatures of the cranberry regions of the United States in 

relation to the growth of certain fungi. In Jour. Agr. Research, 
v. 11, no. 10, p. 521-529. 3 fig. 
20 



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